diff --git a/bun.lockb b/bun.lockb
index afbfed6..756881b 100755
Binary files a/bun.lockb and b/bun.lockb differ
diff --git a/package.json b/package.json
index e848a36..a9966be 100644
--- a/package.json
+++ b/package.json
@@ -33,12 +33,12 @@
     "format:check": "FORCE_COLOR=1 prettier --check .",
     "lint": "eslint .",
     "lint:fix": "eslint --fix .",
-    "test": "yarn build && ts-jest",
+    "test": "yarn build && jest .",
     "upgrade": "bunx npm-check-updates -i"
   },
   "dependencies": {
     "@ledgerhq/hw-transport": "6.30.6",
-    "@zondax/ledger-js": "^0.8.0",
+    "@zondax/ledger-js": "^0.8.1",
     "axios": "^1.6.8"
   },
   "devDependencies": {
diff --git a/src/common.ts b/src/common.ts
index 5bc6c9a..20ec7e2 100644
--- a/src/common.ts
+++ b/src/common.ts
@@ -17,6 +17,10 @@ import type Transport from '@ledgerhq/hw-transport'
  *  limitations under the License.
  ******************************************************************************* */
 
+export type TransactionMetadataBlob = Buffer
+export type TransactionBlob = Buffer
+export type SS58Prefix = number
+
 /**
  * @deprecated Moved to @zondax/ledger-js
  */
diff --git a/src/generic_app.ts b/src/generic_app.ts
index 5486f7a..4125cc2 100644
--- a/src/generic_app.ts
+++ b/src/generic_app.ts
@@ -1,6 +1,5 @@
 /** ******************************************************************************
- *  (c) 2019 - 2022 Zondax AG
- *  (c) 2016-2017 Ledger
+ *  (c) 2019 - 2024 Zondax AG
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -17,12 +16,18 @@
 import axios from 'axios'
 
 import type Transport from '@ledgerhq/hw-transport'
-import BaseApp, { INSGeneric, LedgerError, numbersToBip32Path, processErrorResponse, processResponse } from '@zondax/ledger-js'
+import BaseApp, { BIP32Path, INSGeneric, LedgerError, processErrorResponse, processResponse } from '@zondax/ledger-js'
 import { ResponseError } from '@zondax/ledger-js/dist/responseError'
 
-import { GenericResponseSign, GenericeResponseAddress, P1_VALUES, TxMetadata } from './common'
-
-const GenericAppName = 'Polkadot'
+import {
+  GenericResponseSign,
+  GenericeResponseAddress,
+  P1_VALUES,
+  SS58Prefix,
+  TransactionBlob,
+  TransactionMetadataBlob,
+  TxMetadata,
+} from './common'
 
 export class PolkadotGenericApp extends BaseApp {
   static _INS = {
@@ -40,17 +45,17 @@ export class PolkadotGenericApp extends BaseApp {
     requiredPathLengths: [5],
   }
 
+  txMetadataChainId?: string
   txMetadataSrvUrl?: string
-  txMetadataChainId: string
 
   /**
    * Constructs a new PolkadotGenericApp instance.
-   * @param {Transport} transport - The transport instance.
-   * @param {string} txMetadataChainId - The chain ID in the transaction metadata service.
-   * @param {string} [txMetadataSrvUrl] - The optional transaction metadata service URL.
+   * @param transport - The transport instance.
+   * @param txMetadataChainId - The chain ID in the transaction metadata service.
+   * @param txMetadataSrvUrl - The optional transaction metadata service URL.
    * @throws {Error} - If the transport is not defined.
    */
-  constructor(transport: Transport, txMetadataChainId: string, txMetadataSrvUrl?: string) {
+  constructor(transport: Transport, txMetadataChainId?: string, txMetadataSrvUrl?: string) {
     super(transport, PolkadotGenericApp._params)
     this.txMetadataSrvUrl = txMetadataSrvUrl
     this.txMetadataChainId = txMetadataChainId
@@ -62,18 +67,28 @@ export class PolkadotGenericApp extends BaseApp {
 
   /**
    * Retrieves transaction metadata from the metadata service.
-   * @param {Buffer} txBlob - The transaction blob.
-   * @returns {Promise<Buffer>} - The transaction metadata.
-   * @throws {Error} - If the txMetadataSrvUrl is not defined.
+   * @param txBlob - The transaction blob.
+   * @returns The transaction metadata.
+   * @throws {ResponseError} - If the txMetadataSrvUrl is not defined.
    */
-  async getTxMetadata(txBlob: Buffer): Promise<Buffer> {
-    if (this.txMetadataSrvUrl === undefined) {
-      throw new Error('txMetadataSrvUrl is not defined')
+  async getTxMetadata(txBlob: TransactionBlob, txMetadataChainId: string, txMetadataSrvUrl: string): Promise<TransactionMetadataBlob> {
+    if (!txMetadataSrvUrl) {
+      throw new ResponseError(
+        LedgerError.GenericError,
+        'txMetadataSrvUrl is not defined or is empty. The use of the method requires access to a metadata shortening service.'
+      )
     }
 
-    const resp = await axios.post<TxMetadata>(this.txMetadataSrvUrl, {
+    if (!txMetadataChainId) {
+      throw new ResponseError(
+        LedgerError.GenericError,
+        'txMetadataChainId is not defined or is empty. These values are configured in the metadata shortening service. Check the corresponding configuration in the service.'
+      )
+    }
+
+    const resp = await axios.post<TxMetadata>(txMetadataSrvUrl, {
       txBlob: txBlob.toString('hex'),
-      chain: { id: this.txMetadataChainId },
+      chain: { id: txMetadataChainId },
     })
 
     let txMetadata = resp.data.txMetadata
@@ -86,13 +101,13 @@ export class PolkadotGenericApp extends BaseApp {
 
   /**
    * Retrieves the address for a given BIP44 path and SS58 prefix.
-   * @param {string} bip44Path - The BIP44 path.
-   * @param {number} ss58prefix - The SS58 prefix, must be an integer up to 65535.
-   * @param {boolean} [showAddrInDevice=false] - Whether to show the address on the device.
-   * @returns {Promise<GenericeResponseAddress>} - The address response.
+   * @param bip44Path - The BIP44 path.
+   * @param ss58prefix - The SS58 prefix, must be an integer up to 65535.
+   * @param showAddrInDevice - Whether to show the address on the device.
+   * @returns The address response.
    * @throws {ResponseError} If the response from the device indicates an error.
    */
-  async getAddress(bip44Path: string, ss58prefix: number, showAddrInDevice = false): Promise<GenericeResponseAddress> {
+  async getAddress(bip44Path: BIP32Path, ss58prefix: SS58Prefix, showAddrInDevice = false): Promise<GenericeResponseAddress> {
     // needs to be integer, and up to 65535
     if (!Number.isInteger(ss58prefix) || ss58prefix < 0 || ss58prefix >> 16 !== 0) {
       throw new ResponseError(
@@ -139,7 +154,7 @@ export class PolkadotGenericApp extends BaseApp {
     return chunks
   }
 
-  private getSignReqChunks(path: string, txBlob: Buffer, metadata?: Buffer) {
+  private getSignReqChunks(path: BIP32Path, txBlob: TransactionBlob, metadata?: TransactionMetadataBlob) {
     const chunks: Buffer[] = []
     const bip44Path = this.serializePath(path)
 
@@ -159,13 +174,19 @@ export class PolkadotGenericApp extends BaseApp {
 
   /**
    * Signs a transaction blob.
-   * @param {string} path - The BIP44 path.
-   * @param {number} ins - The instruction for signing.
-   * @param {Buffer} blob - The transaction blob.
-   * @param {Buffer} [metadata] - The optional metadata.
-   * @returns {Promise<GenericResponseSign>} - The response containing the signature and status.
+   * @param path - The BIP44 path.
+   * @param ins - The instruction for signing.
+   * @param blob - The transaction blob.
+   * @param metadata - The optional metadata.
+   * @throws {ResponseError} If the response from the device indicates an error.
+   * @returns The response containing the signature and status.
    */
-  private async signImpl(path: string, ins: number, blob: Buffer, metadata?: Buffer): Promise<GenericResponseSign> {
+  private async signImpl(
+    path: BIP32Path,
+    ins: number,
+    blob: TransactionBlob,
+    metadata?: TransactionMetadataBlob
+  ): Promise<GenericResponseSign> {
     const chunks = this.getSignReqChunks(path, blob, metadata)
 
     try {
@@ -184,34 +205,82 @@ export class PolkadotGenericApp extends BaseApp {
   }
 
   /**
-   * Signs a transaction blob and retrieves the metadata.
-   * @param {string} path - The BIP44 path.
-   * @param {Buffer} txBlob - The transaction blob.
-   * @returns {Promise<GenericResponseSign>} - The response containing the signature and status.
+   * Signs a transaction blob retrieving the correct metadata from a metadata service.
+   * @param path - The BIP44 path.
+   * @param txBlob - The transaction blob.
+   * @throws {ResponseError} If the response from the device indicates an error.
+   * @returns The response containing the signature and status.
    */
-  async sign(path: string, txBlob: Buffer) {
-    const txMetadata = await this.getTxMetadata(txBlob)
+  async sign(path: BIP32Path, txBlob: TransactionBlob) {
+    if (!this.txMetadataSrvUrl) {
+      throw new ResponseError(
+        LedgerError.GenericError,
+        'txMetadataSrvUrl is not defined or is empty. The use of the method requires access to a metadata shortening service.'
+      )
+    }
+
+    if (!this.txMetadataChainId) {
+      throw new ResponseError(
+        LedgerError.GenericError,
+        'txMetadataChainId is not defined or is empty. These values are configured in the metadata shortening service. Check the corresponding configuration in the service.'
+      )
+    }
+
+    const txMetadata = await this.getTxMetadata(txBlob, this.txMetadataSrvUrl, this.txMetadataChainId)
     return await this.signImpl(path, this.INS.SIGN, txBlob, txMetadata)
   }
 
   /**
    * Signs a transaction blob with provided metadata.
-   * @param {string} path - The BIP44 path.
-   * @param {Buffer} txBlob - The transaction blob.
-   * @param {Buffer} txMetadata - The transaction metadata.
-   * @returns {Promise<GenericResponseSign>} - The response containing the signature and status.
+   * @param path - The BIP44 path.
+   * @param txBlob - The transaction blob.
+   * @param txMetadataChainId - The optional chain ID for the transaction metadata service. This value temporarily overrides the one set in the constructor.
+   * @param txMetadataSrvUrl - The optional URL for the transaction metadata service. This value temporarily overrides the one set in the constructor.
+   * @throws {ResponseError} If the response from the device indicates an error.
+   * @returns The response containing the signature and status.
    */
-  async signAdvanced(path: string, txBlob: Buffer, txMetadata: Buffer) {
+  async signMigration(path: BIP32Path, txBlob: TransactionBlob, txMetadataChainId?: string, txMetadataSrvUrl?: string) {
+    if (!this.txMetadataSrvUrl) {
+      throw new ResponseError(
+        LedgerError.GenericError,
+        'txMetadataSrvUrl is not defined or is empty. The use of the method requires access to a metadata shortening service.'
+      )
+    }
+
+    if (!this.txMetadataChainId) {
+      throw new ResponseError(
+        LedgerError.GenericError,
+        'txMetadataChainId is not defined or is empty. These values are configured in the metadata shortening service. Check the corresponding configuration in the service.'
+      )
+    }
+
+    const txMetadata = await this.getTxMetadata(
+      txBlob,
+      txMetadataChainId ?? this.txMetadataChainId,
+      txMetadataSrvUrl ?? this.txMetadataSrvUrl
+    )
     return await this.signImpl(path, this.INS.SIGN, txBlob, txMetadata)
   }
-
   /**
    * Signs a raw transaction blob.
-   * @param {string} path - The BIP44 path.
-   * @param {Buffer} txBlob - The transaction blob.
-   * @returns {Promise<GenericResponseSign>} - The response containing the signature and status.
+   * @param path - The BIP44 path.
+   * @param txBlob - The transaction blob.
+   * @throws {ResponseError} If the response from the device indicates an error.
+   * @returns The response containing the signature and status.
    */
-  async signRaw(path: string, txBlob: Buffer) {
+  async signRaw(path: BIP32Path, txBlob: TransactionBlob) {
     return await this.signImpl(path, this.INS.SIGN_RAW, txBlob)
   }
+
+  /**
+   * [Expert-only Method] Signs a transaction blob with provided metadata (this could be used also with a migration app)
+   * @param path - The BIP44 path.
+   * @param txBlob - The transaction blob.
+   * @param txMetadata - The transaction metadata.
+   * @throws {ResponseError} If the response from the device indicates an error.
+   * @returns The response containing the signature and status.
+   */
+  async signWithMetadata(path: BIP32Path, txBlob: TransactionBlob, txMetadata: TransactionMetadataBlob) {
+    return await this.signImpl(path, this.INS.SIGN, txBlob, txMetadata)
+  }
 }
diff --git a/src/generic_legacy.ts b/src/generic_legacy.ts
index ae1f0cf..482eb5d 100644
--- a/src/generic_legacy.ts
+++ b/src/generic_legacy.ts
@@ -15,20 +15,39 @@
  *  limitations under the License.
  ******************************************************************************* */
 import Transport from '@ledgerhq/hw-transport'
-import { LedgerError, ResponseError, numbersToBip32Path } from '@zondax/ledger-js'
+import { BIP32Path, LedgerError, ResponseError, numbersToBip32Path } from '@zondax/ledger-js'
 
-import { ISubstrateAppLegacy, ResponseAddress, ResponseBase, ResponseSign, ResponseVersion, SCHEME } from './common'
+import { ISubstrateAppLegacy, ResponseAddress, ResponseBase, ResponseSign, ResponseVersion, SCHEME, TransactionBlob } from './common'
 import { PolkadotGenericApp } from './generic_app'
 
+/**
+ * Class representing a legacy Polkadot generic application.
+ * Implements the ISubstrateAppLegacy interface.
+ * @deprecated Use PolkadotGenericApp from generic_app.ts instead.
+ */
 export class PolkadotGenericAppLegacy implements ISubstrateAppLegacy {
   genericApp: PolkadotGenericApp
   ss58prefix: number
 
+  /**
+   * Constructs a new PolkadotGenericAppLegacy instance.
+   * @param transport - The transport instance.
+   * @param ss58prefix - The SS58 prefix.
+   * @param txMetadataChainId - The chain ID in the transaction metadata service.
+   * @param txMetadataSrvUrl - The optional transaction metadata service URL.
+   * @deprecated Use PolkadotGenericApp constructor from generic_app.ts instead.
+   */
   constructor(transport: Transport, ss58prefix: number, txMetadataChainId: string, txMetadataSrvUrl: string | undefined) {
     this.genericApp = new PolkadotGenericApp(transport, txMetadataChainId, txMetadataSrvUrl)
     this.ss58prefix = ss58prefix
   }
 
+  /**
+   * Converts a ResponseError to a legacy ResponseBase format.
+   * @param e - The ResponseError instance.
+   * @returns The legacy ResponseBase object.
+   * @deprecated
+   */
   private convertToLegacyError(e: ResponseError): ResponseBase {
     return {
       error_message: e.errorMessage,
@@ -36,10 +55,23 @@ export class PolkadotGenericAppLegacy implements ISubstrateAppLegacy {
     }
   }
 
-  private convertLegacyPath(account: number, change: number, addressIndex: number) {
+  /**
+   * Converts account, change, and addressIndex to a BIP32Path.
+   * @param account - The account number.
+   * @param change - The change number.
+   * @param addressIndex - The address index.
+   * @returns The BIP32Path.
+   * @deprecated
+   */
+  private convertLegacyPath(account: number, change: number, addressIndex: number): BIP32Path {
     return numbersToBip32Path([0x8000002c, 0x80000162, account, change, addressIndex])
   }
 
+  /**
+   * Retrieves the version of the application.
+   * @returns A promise that resolves to a ResponseVersion object.
+   * @deprecated Use getVersion method from PolkadotGenericApp in generic_app.ts instead.
+   */
   async getVersion(): Promise<ResponseVersion> {
     try {
       const version = await this.genericApp.getVersion()
@@ -67,6 +99,11 @@ export class PolkadotGenericAppLegacy implements ISubstrateAppLegacy {
     }
   }
 
+  /**
+   * Retrieves application information.
+   * @returns A promise that resolves to an object containing application information.
+   * @deprecated Use appInfo method from PolkadotGenericApp in generic_app.ts instead.
+   */
   async appInfo(): Promise<any> {
     try {
       const info = await this.genericApp.appInfo()
@@ -84,6 +121,17 @@ export class PolkadotGenericAppLegacy implements ISubstrateAppLegacy {
     }
   }
 
+  /**
+   * Retrieves the address for a given account, change, and address index.
+   * @param account - The account number.
+   * @param change - The change number.
+   * @param addressIndex - The address index.
+   * @param requireConfirmation - Whether to require confirmation on the device.
+   * @param scheme - The cryptographic scheme.
+   * @returns A promise that resolves to a ResponseAddress object.
+   * @throws {ResponseError} If the scheme is not supported.
+   * @deprecated Use getAddress method from PolkadotGenericApp in generic_app.ts instead.
+   */
   async getAddress(
     account: number,
     change: number,
@@ -114,7 +162,18 @@ export class PolkadotGenericAppLegacy implements ISubstrateAppLegacy {
     }
   }
 
-  async sign(account: number, change: number, addressIndex: number, message: Buffer, scheme?: SCHEME): Promise<ResponseSign> {
+  /**
+   * Signs a transaction blob.
+   * @param account - The account number.
+   * @param change - The change number.
+   * @param addressIndex - The address index.
+   * @param message - The transaction blob.
+   * @param scheme - The cryptographic scheme.
+   * @returns A promise that resolves to a ResponseSign object.
+   * @throws {ResponseError} If the scheme is not supported.
+   * @deprecated Use sign method from PolkadotGenericApp in generic_app.ts instead.
+   */
+  async sign(account: number, change: number, addressIndex: number, message: TransactionBlob, scheme?: SCHEME): Promise<ResponseSign> {
     try {
       if (scheme !== SCHEME.ED25519) {
         throw ResponseError.fromReturnCode(LedgerError.AlgorithmNotSupported)
@@ -137,7 +196,18 @@ export class PolkadotGenericAppLegacy implements ISubstrateAppLegacy {
     }
   }
 
-  async signRaw(account: number, change: number, addressIndex: number, message: Buffer, scheme?: SCHEME): Promise<ResponseSign> {
+  /**
+   * Signs a raw transaction blob.
+   * @param account - The account number.
+   * @param change - The change number.
+   * @param addressIndex - The address index.
+   * @param message - The transaction blob.
+   * @param scheme - The cryptographic scheme.
+   * @returns A promise that resolves to a ResponseSign object.
+   * @throws {ResponseError} If the scheme is not supported.
+   * @deprecated Use signRaw method from PolkadotGenericApp in generic_app.ts instead.
+   */
+  async signRaw(account: number, change: number, addressIndex: number, message: TransactionBlob, scheme?: SCHEME): Promise<ResponseSign> {
     try {
       if (scheme !== SCHEME.ED25519) {
         throw ResponseError.fromReturnCode(LedgerError.AlgorithmNotSupported)
diff --git a/src/index.ts b/src/index.ts
index 71e1de4..d97f08d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -17,5 +17,6 @@
 
 export * from './legacy_apps'
 export * from './generic_app'
+export * from './generic_legacy'
 export { SubstrateApp } from './substrate_app'
-export { newSubstrateApp, newMigrationGenericApp, supportedApps } from './supported_apps'
+export { newSubstrateApp, supportedApps } from './supported_apps'
diff --git a/src/substrate_app.ts b/src/substrate_app.ts
index cddc864..d2de929 100644
--- a/src/substrate_app.ts
+++ b/src/substrate_app.ts
@@ -34,11 +34,20 @@ import {
   processErrorResponse,
 } from './common'
 
+/**
+ * Class representing a Substrate application.
+ */
 export class SubstrateApp implements ISubstrateAppLegacy {
   transport: Transport
   cla: number
   slip0044: number
 
+  /**
+   * Create a SubstrateApp instance.
+   * @param transport - The transport instance.
+   * @param cla - The CLA value.
+   * @param slip0044 - The SLIP-0044 value.
+   */
   constructor(transport: Transport, cla: number, slip0044: number) {
     if (transport == null) {
       throw new Error('Transport has not been defined')
@@ -48,6 +57,14 @@ export class SubstrateApp implements ISubstrateAppLegacy {
     this.slip0044 = slip0044
   }
 
+  /**
+   * Serialize the BIP44 path.
+   * @param slip0044 - The SLIP-0044 value.
+   * @param account - The account index.
+   * @param change - The change index.
+   * @param addressIndex - The address index.
+   * @returns The serialized path.
+   */
   static serializePath(slip0044: number, account: number, change: number, addressIndex: number) {
     if (!Number.isInteger(account)) throw new Error('Input must be an integer')
     if (!Number.isInteger(change)) throw new Error('Input must be an integer')
@@ -62,6 +79,11 @@ export class SubstrateApp implements ISubstrateAppLegacy {
     return buf
   }
 
+  /**
+   * Split a message into chunks.
+   * @param message - The message to split.
+   * @returns The message chunks.
+   */
   static GetChunks(message: Buffer) {
     const chunks = []
     const buffer = Buffer.from(message)
@@ -77,6 +99,15 @@ export class SubstrateApp implements ISubstrateAppLegacy {
     return chunks
   }
 
+  /**
+   * Get chunks for signing.
+   * @param slip0044 - The SLIP-0044 value.
+   * @param account - The account index.
+   * @param change - The change index.
+   * @param addressIndex - The address index.
+   * @param message - The message to sign.
+   * @returns The chunks for signing.
+   */
   static signGetChunks(slip0044: number, account: number, change: number, addressIndex: number, message: Buffer) {
     const chunks = []
     const bip44Path = SubstrateApp.serializePath(slip0044, account, change, addressIndex)
@@ -85,6 +116,10 @@ export class SubstrateApp implements ISubstrateAppLegacy {
     return chunks
   }
 
+  /**
+   * Get the version of the application.
+   * @returns The version response.
+   */
   async getVersion(): Promise<ResponseVersion> {
     try {
       return await getVersion(this.transport, this.cla)
@@ -93,6 +128,10 @@ export class SubstrateApp implements ISubstrateAppLegacy {
     }
   }
 
+  /**
+   * Get application information.
+   * @returns The application information.
+   */
   async appInfo() {
     return await this.transport.send(0xb0, 0x01, 0, 0).then(response => {
       const errorCodeData = response.subarray(-2)
@@ -126,23 +165,27 @@ export class SubstrateApp implements ISubstrateAppLegacy {
       return {
         return_code: returnCode,
         error_message: errorCodeToString(returnCode),
-        // //
         appName: appName === '' || 'err',
         appVersion: appVersion === '' || 'err',
         flagLen,
         flagsValue,
-        // eslint-disable-next-line no-bitwise
         flag_recovery: (flagsValue & 1) !== 0,
-        // eslint-disable-next-line no-bitwise
         flag_signed_mcu_code: (flagsValue & 2) !== 0,
-        // eslint-disable-next-line no-bitwise
         flag_onboarded: (flagsValue & 4) !== 0,
-        // eslint-disable-next-line no-bitwise
         flag_pin_validated: (flagsValue & 128) !== 0,
       }
     }, processErrorResponse)
   }
 
+  /**
+   * Get the address.
+   * @param account - The account index.
+   * @param change - The change index.
+   * @param addressIndex - The address index.
+   * @param [requireConfirmation=false] - Whether confirmation is required.
+   * @param [scheme=SCHEME.ED25519] - The scheme.
+   * @returns The address response.
+   */
   async getAddress(
     account: number,
     change: number,
@@ -171,6 +214,16 @@ export class SubstrateApp implements ISubstrateAppLegacy {
     }, processErrorResponse)
   }
 
+  /**
+   * Send a chunk for signing.
+   * @private
+   * @param chunkIdx - The chunk index.
+   * @param chunkNum - The total number of chunks.
+   * @param chunk - The chunk data.
+   * @param [scheme=SCHEME.ED25519] - The scheme.
+   * @param [ins=INS.SIGN] - The instruction.
+   * @returns The response.
+   */
   private async signSendChunk(chunkIdx: number, chunkNum: number, chunk: Buffer, scheme = SCHEME.ED25519, ins: INS_SIGN = INS.SIGN) {
     let payloadType = PAYLOAD_TYPE.ADD
     if (chunkIdx === 1) {
@@ -203,6 +256,17 @@ export class SubstrateApp implements ISubstrateAppLegacy {
     }, processErrorResponse)
   }
 
+  /**
+   * Implementation of the signing process.
+   * @private
+   * @param account - The account index.
+   * @param change - The change index.
+   * @param addressIndex - The address index.
+   * @param message - The message to sign.
+   * @param ins - The instruction.
+   * @param [scheme=SCHEME.ED25519] - The scheme.
+   * @returns The signing response.
+   */
   private async signImpl(
     account: number,
     change: number,
@@ -229,16 +293,36 @@ export class SubstrateApp implements ISubstrateAppLegacy {
     }, processErrorResponse)
   }
 
+  /**
+   * Sign a message.
+   * @param account - The account index.
+   * @param change - The change index.
+   * @param addressIndex - The address index.
+   * @param message - The message to sign.
+   * @param [scheme=SCHEME.ED25519] - The scheme.
+   * @returns The signing response.
+   */
   async sign(account: number, change: number, addressIndex: number, message: Buffer, scheme = SCHEME.ED25519) {
     return await this.signImpl(account, change, addressIndex, message, INS.SIGN, scheme)
   }
 
+  /**
+   * Sign a raw message.
+   * @param account - The account index.
+   * @param change - The change index.
+   * @param addressIndex - The address index.
+   * @param message - The message to sign.
+   * @param [scheme=SCHEME.ED25519] - The scheme.
+   * @returns The signing response.
+   */
   async signRaw(account: number, change: number, addressIndex: number, message: Buffer, scheme = SCHEME.ED25519) {
     return await this.signImpl(account, change, addressIndex, message, INS.SIGN_RAW, scheme)
   }
 
   /**
    * @deprecated This function is deprecated and will be removed in future versions.
+   * Get the allowlist public key.
+   * @returns The allowlist public key response.
    */
   async getAllowlistPubKey(): Promise<ResponseAllowlistPubKey> {
     return await this.transport.send(this.cla, INS.ALLOWLIST_GET_PUBKEY, 0, 0).then(response => {
@@ -266,6 +350,9 @@ export class SubstrateApp implements ISubstrateAppLegacy {
 
   /**
    * @deprecated This function is deprecated and will be removed in future versions.
+   * Set the allowlist public key.
+   * @param pk - The public key.
+   * @returns The response.
    */
   async setAllowlistPubKey(pk: Buffer) {
     return await this.transport.send(this.cla, INS.ALLOWLIST_SET_PUBKEY, 0, 0, pk).then(response => {
@@ -281,6 +368,8 @@ export class SubstrateApp implements ISubstrateAppLegacy {
 
   /**
    * @deprecated This function is deprecated and will be removed in future versions.
+   * Get the allowlist hash.
+   * @returns The allowlist hash response.
    */
   async getAllowlistHash(): Promise<ResponseAllowlistHash> {
     return await this.transport.send(this.cla, INS.ALLOWLIST_GET_HASH, 0, 0).then(response => {
@@ -308,6 +397,11 @@ export class SubstrateApp implements ISubstrateAppLegacy {
 
   /**
    * @deprecated This function is deprecated and will be removed in future versions.
+   * Send a chunk for uploading the allowlist.
+   * @param chunkIdx - The chunk index.
+   * @param chunkNum - The total number of chunks.
+   * @param chunk - The chunk data.
+   * @returns The response.
    */
   async uploadSendChunk(chunkIdx: number, chunkNum: number, chunk: Buffer) {
     let payloadType = PAYLOAD_TYPE.ADD
@@ -332,6 +426,9 @@ export class SubstrateApp implements ISubstrateAppLegacy {
 
   /**
    * @deprecated This function is deprecated and will be removed in future versions.
+   * Upload the allowlist.
+   * @param message - The allowlist message.
+   * @returns The response.
    */
   async uploadAllowlist(message: Buffer) {
     const chunks: Buffer[] = []
@@ -347,7 +444,6 @@ export class SubstrateApp implements ISubstrateAppLegacy {
       }
 
       for (let i = 1; i < chunks.length; i += 1) {
-        // eslint-disable-next-line no-await-in-loop,no-param-reassign
         result = await this.uploadSendChunk(1 + i, chunks.length, chunks[i])
         if (result.return_code !== ERROR_CODE.NoError) {
           break
diff --git a/src/supported_apps.ts b/src/supported_apps.ts
index 6cf88ec..2e96de1 100644
--- a/src/supported_apps.ts
+++ b/src/supported_apps.ts
@@ -17,7 +17,6 @@
 import type Transport from '@ledgerhq/hw-transport'
 
 import { type SubstrateAppParams } from './common'
-import { PolkadotGenericApp } from './generic_app'
 import { SubstrateApp } from './substrate_app'
 
 export function newSubstrateApp(transport: Transport, chainName: string) {
diff --git a/tests/integration.test.ts b/tests/integration.test.ts
index 9f58630..e52786f 100644
--- a/tests/integration.test.ts
+++ b/tests/integration.test.ts
@@ -1,4 +1,3 @@
-// TODO: Use mock transport
 // /** ******************************************************************************
 //  *  (c) 2018 - 2022 Zondax AG
 //  *
@@ -15,11 +14,10 @@
 //  *  limitations under the License.
 //  ******************************************************************************* */
 // import { blake2bFinal, blake2bInit, blake2bUpdate } from 'blakejs'
-
-// import { MockTransport } from '@ledgerhq/hw-transport-mocker'
 // import { ed25519 } from '@noble/curves/ed25519'
 
 // import { newSubstrateApp } from '../src'
+// import { openTransportReplayer, RecordStore } from '@ledgerhq/hw-transport-mocker'
 
 // const CHAIN = 'Kusama'
 // const YOUR_PUBKEY = 'd280b24dface41f31006e5a2783971fc5a66c862dd7d08f97603d2902b75e47a'
@@ -27,13 +25,22 @@
 // const YOUR_BLOB =
 //   '040000313233343536373839303132333435363738393031323334353637383930313233158139ae28a3dfaac5fe1560a5e9e05cd5038d2433158139ae28a3dfaac5fe1560a5e9e05c362400000c000000b0a8d493285c2df73290dfb7e61f870f17b41801197a149ca93654499ea3dafeb0a8d493285c2df73290dfb7e61f870f17b41801197a149ca93654499ea3dafe'
 
-// let transport = {}
-
 // jest.setTimeout(60000)
 
 // describe('Integration', function () {
 //   test('get version', async () => {
-//     // @ts-expect-error transport will be there
+//     const store = RecordStore.fromString(`
+//     => e016000000
+//     <= 000000050107426974636f696e034254439000
+//     => e001000000
+//     <= 3110000405312e352e35042300000004312e37002013fe17e06cf2f710d33328aa46d1053f8fadd48dcaeca2c5512dd79e2158d5779000
+//   `,
+//       {
+//         autoSkipUnknownApdu: true,
+//       }
+//     );
+//     const transport = await openTransportReplayer(store)
+
 //     const app = newSubstrateApp(transport, CHAIN)
 //     const resp = await app.getVersion()
 //     console.log(resp)
@@ -47,72 +54,72 @@
 //     expect(resp.test_mode).toEqual(false)
 //   })
 
-//   test('get address', async () => {
-//     // @ts-expect-error transport will be there
-//     const app = newSubstrateApp(transport, CHAIN)
+// //   test('get address', async () => {
+// //     // @ts-expect-error transport will be there
+// //     const app = newSubstrateApp(transport, CHAIN)
 
-//     const pathAccount = 0x80000000
-//     const pathChange = 0x80000000
-//     const pathIndex = 0x80000005
+// //     const pathAccount = 0x80000000
+// //     const pathChange = 0x80000000
+// //     const pathIndex = 0x80000005
 
-//     const response = await app.getAddress(pathAccount, pathChange, pathIndex)
-//     console.log(response)
+// //     const response = await app.getAddress(pathAccount, pathChange, pathIndex)
+// //     console.log(response)
 
-//     expect(response.return_code).toEqual(0x9000)
-//     expect(response.error_message).toEqual('No errors')
-//     expect(response).toHaveProperty('pubKey')
-//     expect(response.pubKey).toEqual(YOUR_PUBKEY)
-//     expect(response.address).toEqual(YOUR_ADDRESS)
-//   })
+// //     expect(response.return_code).toEqual(0x9000)
+// //     expect(response.error_message).toEqual('No errors')
+// //     expect(response).toHaveProperty('pubKey')
+// //     expect(response.pubKey).toEqual(YOUR_PUBKEY)
+// //     expect(response.address).toEqual(YOUR_ADDRESS)
+// //   })
 
-//   test('show address', async () => {
-//     // @ts-expect-error transport will be there
-//     const app = newSubstrateApp(transport, CHAIN)
+// //   test('show address', async () => {
+// //     // @ts-expect-error transport will be there
+// //     const app = newSubstrateApp(transport, CHAIN)
 
-//     const pathAccount = 0x80000000
-//     const pathChange = 0x80000000
-//     const pathIndex = 0x80000005
-//     const response = await app.getAddress(pathAccount, pathChange, pathIndex, true)
+// //     const pathAccount = 0x80000000
+// //     const pathChange = 0x80000000
+// //     const pathIndex = 0x80000005
+// //     const response = await app.getAddress(pathAccount, pathChange, pathIndex, true)
 
-//     console.log(response)
+// //     console.log(response)
 
-//     expect(response.return_code).toEqual(0x9000)
-//     expect(response.error_message).toEqual('No errors')
+// //     expect(response.return_code).toEqual(0x9000)
+// //     expect(response.error_message).toEqual('No errors')
 
-//     expect(response).toHaveProperty('address')
-//     expect(response).toHaveProperty('pubKey')
+// //     expect(response).toHaveProperty('address')
+// //     expect(response).toHaveProperty('pubKey')
 
-//     expect(response.pubKey).toEqual(YOUR_PUBKEY)
-//     expect(response.address).toEqual(YOUR_ADDRESS)
-//   })
+// //     expect(response.pubKey).toEqual(YOUR_PUBKEY)
+// //     expect(response.address).toEqual(YOUR_ADDRESS)
+// //   })
 
-//   test('sign2_and_verify', async () => {
-//     const txBlob = Buffer.from(YOUR_BLOB, 'hex')
+// //   test('sign2_and_verify', async () => {
+// //     const txBlob = Buffer.from(YOUR_BLOB, 'hex')
 
-//     // @ts-expect-error transport will be there
-//     const app = newSubstrateApp(transport, CHAIN)
+// //     // @ts-expect-error transport will be there
+// //     const app = newSubstrateApp(transport, CHAIN)
 
-//     const pathAccount = 0x80000000
-//     const pathChange = 0x80000000
-//     const pathIndex = 0x80000000
+// //     const pathAccount = 0x80000000
+// //     const pathChange = 0x80000000
+// //     const pathIndex = 0x80000000
 
-//     const responseAddr = await app.getAddress(pathAccount, pathChange, pathIndex)
-//     const responseSign = await app.sign(pathAccount, pathChange, pathIndex, txBlob)
+// //     const responseAddr = await app.getAddress(pathAccount, pathChange, pathIndex)
+// //     const responseSign = await app.sign(pathAccount, pathChange, pathIndex, txBlob)
 
-//     const pubkey = responseAddr.pubKey
+// //     const pubkey = responseAddr.pubKey
 
-//     console.log(responseAddr)
-//     console.log(responseSign)
+// //     console.log(responseAddr)
+// //     console.log(responseSign)
 
-//     // Check signature is valid
-//     let prehash = txBlob
-//     if (txBlob.length > 256) {
-//       const context = blake2bInit(32)
-//       blake2bUpdate(context, txBlob)
-//       prehash = Buffer.from(blake2bFinal(context))
-//     }
+// //     // Check signature is valid
+// //     let prehash = txBlob
+// //     if (txBlob.length > 256) {
+// //       const context = blake2bInit(32)
+// //       blake2bUpdate(context, txBlob)
+// //       prehash = Buffer.from(blake2bFinal(context))
+// //     }
 
-//     const valid = await ed25519.verify(responseSign.signature.subarray(1), prehash, pubkey)
-//     expect(valid).toEqual(true)
-//   })
+// //     const valid = ed25519.verify(responseSign.signature.subarray(1), prehash, pubkey)
+// //     expect(valid).toEqual(true)
+// //   })
 // })
diff --git a/yarn.lock b/yarn.lock
index 880a25d..a004eaf 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1119,10 +1119,10 @@
     "@typescript-eslint/types" "7.9.0"
     eslint-visitor-keys "^3.4.3"
 
-"@zondax/ledger-js@^0.8.0":
-  version "0.8.0"
-  resolved "https://registry.yarnpkg.com/@zondax/ledger-js/-/ledger-js-0.8.0.tgz#cca9182ce5bd89d00800d5db098193183ec477a1"
-  integrity sha512-G61wAtj5mBI3EbBe3wB2NXfA4fkBxjxexiCaLOa+akNNhYH0kWFImI7oWfQGMt+epQatvBLg5h0sgNLVge+GRQ==
+"@zondax/ledger-js@^0.8.1":
+  version "0.8.1"
+  resolved "https://registry.yarnpkg.com/@zondax/ledger-js/-/ledger-js-0.8.1.tgz#b4d09d7778592ce350f8646713ff3a9ee069f0ef"
+  integrity sha512-mr/lHdN73UzsY4FkUOAoCyP5GsxCTbCCKv+fQfE+ENOxI+iv5raFB+V7cCbhKuQdH6kdKhT+wYD2zA6Jv19rGQ==
   dependencies:
     "@ledgerhq/hw-transport" "6.30.6"